Seattle Mariners pitching prospect Brandon Maurer threw five shutout innings on Monday, blowing away the Cincinnati Reds as part of a 16-0 victory. He fanned seven, giving up six hits and a walk. Overall this spring, Maurer has thrown 20 innings with a 0.90 ERA and a 22/6 K/BB ratio, making it pretty tough for the Mariners to say no to him as the fifth starter.
Here is what I wrote about Maurer in the 2013 Baseball Prospect Book:
Brandon Maurer, RHP, Seattle Mariners
Bats: R Throws: R HT: 6-5 WT: 200 DOB: July 3, 1990
2012: Grade C
Injuries hampered Brandon Maurer for most of his career, but he was healthy in 2012 and logged in a very successful season in Double-A. A 23rd round pick from high school in Orange, California, in 2008, Maurer has always intrigued scouts with his 93-96 MPH fastball. He could never stay healthy long enough to fully develop his secondary pitches, but that changed last year. His curveball, slider, and changeup all showed significant improvement, giving him four major league pitches. His command was generally solid for Jackson, and there were no statistical red flags to call the positive scouting reports in question. He has both elbow and shoulder problems on his resume, but if he avoids further injury, Maurer looks like a solid number three starter. Grade B.
ADDITIONAL COMMENT: Maurer has been everything the Mariners could have hoped this spring. Does he need Triple-A time? He went 9-2, 3.20 in 138 innings with a 117/48 K/BB and 133 hits allowed last year for Double-A Jackson, quite solid, and he's always been statistically effective in the low minors. His stuff is quality, and he knows how to pitch. The biggest problem has always been simple health; it has never been about velocity, movement, or pitchability. Before his 138 innings last year, his career high was 79.
Ideally speaking, I think most players need time in Triple-A and I don't see how 10-15 starts in Tacoma would hurt him. But it is also hard to say "you must go back to the minors" considering his spring performance and what he did last year. There is also the risk his arm will fall off again, so perhaps the thing to do is use him in the majors now since he looks ready, deploying those solid innings in Seattle rather than Tacoma.